Fusaria of Potatoes 109 



a true Fusarium never was observed which would produce a typical 

 coremium 16 or a typical pionnotes, 17 that is, the two fruiting forms on 

 the basis of which the genera Atractium and Pionnotes were founded 

 by their authors and which are now reduced to synonymy by Appel 

 and Wollenweber because these investigators find in the Fusaria certain 

 structures resembling these two forms. 



That one of these forms, Pionnotes, is a distinct form, and that its 

 characters can be used as a basis in a classification of Fusarium-like 

 organisms, has been shown lately by Wollenweber. After citing Fusarium 

 (Pionnotes) udum and its variety as instances of the Fusaria without 

 " Fusszelle," he (1913c: 206) says: " Beilaufig bemerkt, bilden solche 

 Fusarien zusammen mit F. aquaeductum eine gute Section der Gattung, 

 die ich Eupionnotes nenne wegen des Ubergewrichtes dieser Sporenver- 

 lagerung." 



There is very little doubt that a true coremial form of fructification 

 is quite distinct, and does not occur in the species of Fusarium observed 

 by the writer. 



With respect to the present status of the genus Fusarium, some recent 

 changes must be considered here. Wollenweber (1913 a: 33) transferred 

 from the genus Fusarium to the genus Ramularia all forms with conidia 

 of F.dydimum type when chlamydospores are present. 18 The same author 

 (1913 c:225), somewhat later, also excluded from the genus Fusarium 

 forms with conidia of the type of F. Willkommi and transferred them 

 into a new genus, Cylindrocarpon, 19 established for this purpose. Thus, 

 in fact, all forms having cylindrical conidia or conidia with rounded ends 

 are excluded by Wollenweber (1913 c: 239) from the genus Fusarium. 

 The genus Sepedonium Link (1809), according to Wollenweber (1913 c: 

 200), is only a chlamydosporial stage of Fusarium orthoceras. 



It appears, then, from the study of the Fusarium-like organisms of 

 potatoes (which, on the whole, represent a great diversity of forms) and 

 also from a careful survey of the genus Fusarium as it stands in literature, 

 that the following characters are of generic value: 



16 The terminology which is used here is the same as that of Lindau. 



17 Only one Fusarium-like organism was isolated from potatoes which produces a fruiting layer very 

 similar to a pionnotes (F. udum var. Solani), but it is very distinct from all the other Fusaria and can be 

 used rather to support than to disprove the above statement. 



18 In those cases in which chlamydospores are not present, Wollenweber says the fungi have a perithecial 

 stage of the genus Mycosphserella. 



19 This genus is to include only those forms for which a perithecial stage has not yet been found. 

 F. Willkommi has been connected with Nectria galligena. 



